Ian Bell did the steering as England coasted to an emphatic six-wicket win over South Africa at Lord's to take a 2-1 NatWest Series lead.
Alastair Cook's team therefore cannot lose this one-day international contest between the world's top two teams, with just one match left to play at Trent Bridge on Wednesday.
Bell (88) and Jonathan Trott overcame Cook's own early departure, in pursuit of 220 for eight after England's bowlers had given the hosts an obvious chance of a successful run chase.
Ultimately, it was achieved in routine circumstances - with more than three overs to spare - thanks principally to Bell, who shared a second-wicket stand of 141 with Trott.
The latter defied the pain of an injury to his right hand, suffered when Dale Steyn hit him with a short ball and which will necessitate an x-ray tomorrow.
Steyn was also Cook's downfall, the England captain taking his sequence of innings without a half-century - in Tests and ODIs - to nine when he was lbw in the first over to a good delivery which came back up the slope to beat his forward-defence.
South Africa's pace attack were finding sideways movement in the air, and off the pitch. But Bell and Trott appeared in control, and in no hurry, from the outset.
Bell was already well-past his 88-ball 50 when he had his one moment of fortune, dropped by Robin Peterson above his head at mid-on off Lonwabo Tsotsobe.
Even though Trott went soon afterwards, lbw on DRS when he missed a sweep at Dean Elgar's slow left-arm, England stayed in a comfort zone.
Ravi Bopara failed with the bat for the second successive match, driving loosely at Ryan McLaren and edging behind. But if there were any fleeting nerves, they were duly settled by the in-form Eoin Morgan.
There was room for manoeuvre in a batting powerplay which yielded just 18 runs, and Morgan then provided the final push - alongside Craig Kieswetter, who finished the job by clubbing Steyn for a dismissive six off over long-off - after Bell had fallen short of a third ODI hundred when he was athletically caught-behind by AB de Villiers off South Africa's pace spearhead.
As in England's series-levelling victory at The Oval two days ago, it was off-spinner James Tredwell (three for 35) and all-rounder Bopara who were among their most effective bowlers on a pitch offering turn and occasional variable bounce.
A 10.15am start increased the significance of the toss on a day which would prove persistently cloudy, and South Africa openers Hashim Amla and Graeme Smith were required to be conservative.
After three wickets then fell for the addition of only 15 runs in the middle overs, more caution was necessary for the tourists from 115 for four in the 29th.
Amla was yet again the scourge of England's bowlers, and fielders, on his way to South Africa's modest top score of 45.
England dropped the prolific batsman for the sixth time this summer, on four, when Tredwell failed to hang on to a sharp chance away to his right at second slip off Steven Finn.
But after Smith had edged an attempted pull at Jade Dernbach behind - to end a stand of 68, and ensure Tredwell did not pay too dearly for another drop at slip - Bopara twice took the fielders, and the umpire, out of the equation.
He swung one back between Amla's bat and pad, to beat the attempted drive, and hit off-and-middle - and then had Faf du Plessis chopping on for just a single.
In between, number three JP Duminy was deceived by Tredwell as he went out of his ground, failed to cover the turn and was easily stumped.
Tredwell and Kieswetter eventually accounted for De Villiers too, overstretching as he attempted a drive into the offside.
With South Africa's likeliest lad therefore gone at the very start of the last 10 overs, off-spinner and wicketkeeper then made Wayne Parnell another stumping victim.
They became the first to record that hat-trick of dismissals for England in ODIs as Tredwell made up generously for his earlier catching lapses.
Kieswetter and James Anderson ought to have run Peterson out for just a single, and the left-hander made them pay with some late invention.
But South Africa were still significantly short of par.